Combined Tenotomy + Anderson Procedure for Treatment of Acquired Downbeat Nystagmus and Oscillopsia

The tenotomy procedure improves visual acuities and reduces oscillopsia of patients with infantile nystagmus syndrome (INS), acquired pendular nystagmus (APN), and asymmetric, (a)periodic alternating nystagmus (APAN). Our 44-year-old patient had predominantly vertical nystagmus (i.e., downbeat (DBN)), oscillopsia, strabismus, and vertical diplopia of 14 years duration, and adopted a significant chin-down (i.e., upgaze) position for best vision and comfort. Eye-muscle surgery was done in 1993 for diplopia from traumatic 4th N palsy, but no clinical notes were available.